Aldehydes such as acetaldehyde (AA) are volatile organic compounds (VOCs) that are routinely released via many chemical processes occurring in nature as well as in enclosed environments. Since many parts of a vehicle interior are organic polymer materials, aldehydes may be already present in these automotive parts as a result of the manufacturing process or be generated in the parts via photooxidation and thermooxidation during and after post-manufacturing. The generated aldehydes diffuse from their source to the material surface, at which point, aldehydes are released into the cabin air.
While many different VOCs are responsible for the “new car smell,” elevated AA concentrations in the cabin air are one potential source, and are both undesirable and subject to governmental scrutiny. Thus, regulations regarding acceptable AA limits in new vehicle interiors are under consideration in some countries such as China, and AA is a controlled substance in Korea.